The conventional recreational spa or hot tub comprises a water-carrying shell, a base, and a series of vertically-oriented support members secured to the base and supporting the shell. The shell itself comprises a thermoplastic sheet (such as acrylic, polystyrene and Centrex (trade mark)) molded into the desired shape, and a rigidizing layer (such as fibreglass) applied to the underside of the thermoplastic sheet for reinforcement of the shell. Support members (typically wooden blocks), placed into the rigidizing layer while the rigidizing layer is curing, serve as attachment points for the support members. Water jets, fitted to the shell through holes cut therein, are attached to a water pump via suitable hosing for the circulation of water in the spa. Vertical decorative panels secured to the wooden support members conceal the wooden support members, the water pump and the hosing.
A significant problem with the conventional spa is that their construction is very labour intensive. Since the wooden blocks are secured to the shell via the fibreglass layer, the vertical orientation of each block is a function of the consistency in the thickness of the fibreglass layer. Also, since the wooden blocks are inserted by hand into the fibreglass layer, the horizontal orientation of each block is a function of the consistency in placement of the blocks. As a result, each wooden support member must be hand fit to each respective wooden block and the spa base. Further, since the decorative panels are secured to the wooden support members, the resulting variation in placement of the support members must be taken into account during the fitment of the decorative panels. Accordingly, attempts have been made to prefabricate a number of the spa components to increase consistency in the manufacturing process, and thereby reduce manufacturing and assembly costs.
For instance, Hertzog (U.S. Pat. No. 5,010,603) teaches an above-ground swimming pool formed from a series of modular components. The swimming pool comprises a number of prefabricated planar wall panels that are secured end-to-end to form the periphery of the pool. Wooden brace members are secured to the outer surface of the wall panels, at periodic intervals around the pool, to reinforce the wall panels against buckling and to form the basis of a pool deck. A vinyl liner is suspended within the interior of the pool from a bead retainer secured to the top of the wall panels.
Holland (U.S. Pat. No. 6,637,162) teaches a modular spa system comprising a preformed base, and a number of preformed L-shaped braces, preformed lower wall sections, preformed seat sections, and preformed backrest sections. Typically, the spa components are precast from concrete, or other such material. Each L-shaped brace is secured to the perimeter of the base via mounting holes formed in the base. The lower wall sections are disposed vertically around the centre of the base, and supported by the lowermost portion of the L-shaped braces. The seat sections are disposed around the outer perimeter of the lower wall sections, and are support by the horizontal portion of the L-shaped braces. The backrest sections are disposed around the outer perimeter of the seat sections, and are supported by the upper vertical portion of the L-shaped braces. The base, braces, lower wall sections, seat sections, and backrest sections are all sealed together with caulking.
Although both Hertzog and Holland add some consistency to the manufacturing process, both the vinyl liner and the caulking are prone to leakage. Further, the wooden brace members used by Hertzog must still be hand-fit to the wall panels. Also, the significant number of components required by Hertzog and Holland add to the cost of manufacture. Therefore, the remains a need for a mechanism for manufacturing a modular spa that adds consistency to the manufacturing process, while also reducing manufacturing costs.